Patient no. 1 aPTT, chromogenic FVIII results, mean thrombin generation area under the curve (AUC), and FVIII antigen level (ELISA). (Top) There is good correlation between the drop in aPTT and rise in FVIII in the day-2 pretreatment (pre), day-2 1-hour, and day-2 6-hour samples. There is a peak in FVIII activity at the day-3 6-hour sample, and both the aPTT and FVIII return to baseline by the day-10 sample. (Bottom) There is a peak in FVIII:Ag at the day-3 1-hour sample to a level of 0.07 IU/mL (7%). The mean thrombin generation AUC is also shown and begins with the greatest AUC in the baseline sample that most likely reflects the exogenous recombinant FVIII that the patient self-administered 7 days before the start of the study. The AUC steadily declines from that time point on and it is possible that this exogenous factor masked any contribution to overall thrombin generation that the endogenous factor synthesized under the influence of gentamicin could have made. Error bars indicate the standard error of the mean (SEM).